Liquid crystal display with narrow angular range of incident light

ABSTRACT

A liquid crystal display includes a liquid crystal panel in the pixel electrode and common electrodes formed within a pixel comprise repeating structures. The angular range of light incident from the light source is narrower along a direction of the repeating structures than along an orthogonal direction.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display and, moreparticularly, to a liquid crystal display which exhibits an increasedcontrast ratio while maintaining a wide viewing angle.

2. Description of Related Art

Liquid crystal displays are used in various fields, from home use tomedical use, because of their features such as low profile, lightweight, and low power consumption; furthermore, their use is on therise. Generally, in a liquid crystal display, a polarizing plate, liquidcrystals, and a further polarizing plate are arranged in this order on abacklight. The liquid crystal display controls the quantity of lightpassing through the polarizing plate on the exit side by applying avoltage to the liquid crystal and performs display of an image.

The viewing angles of liquid crystal displays are steadily increasingdue to previous technical developments, including in-plane switchingmode (IPS mode) and vertical alignment mode (VA mode) in medicalmonitors, flat-screen televisions and the like. In-plane switching modeliquid crystal displays are preferred at present because of thesmoothness of their viewing angle characteristics.

However, the demands for higher image quality on medical liquid crystalmonitors, flat-screen liquid crystal televisions and the like continueto grow. Examples of requirements for higher-quality display include anincrease in contrast ratio (the ratio between a luminance with whichblack is displayed (black luminance) and a luminance with which white isdisplayed (white luminance)). The contrast ratio increases withincreasing white luminance and decreasing black luminance. That is, asthe contrast ratio increases, the difference between white and blackbecomes clearer, and image quality improves. In particular, a contrastratio of 1,000 or higher is strongly desired for medical monochromeliquid crystal monitors.

A technique for increasing the contrast ratio in a liquid crystaldisplay is described in JP11-337922 (reference 1).

In the liquid crystal display of reference 1, only those lightcomponents whose angles of incidence are less than a predetermined anglerelative to the perpendicular are permitted to impinge on the pixelsfrom the backlight. More specifically, by limiting the angle of lightincident on the liquid crystal panel, the light incident in a moreoblique direction is reduced, and light scattering that would otherwiseoccur within the liquid crystal panel is prevented. As a result theblack luminance is reduced, and in turn the contrast ratio is increased.

However, since the liquid crystal display disclosed in reference limitsthe angle of incident light in all directions parallel to the substrate,the increase in contrast ratio comes at the expense of reduced viewingangle and reduced luminance. The decreases in viewing angle andluminance are serious drawbacks, especially in liquid crystal panelsintended to have a wide viewing angle such as the in-plane switchingmode displays.

SUMMARY OF THE INVENTION

It is an object of the present invention to solve or at least to lessenthe above-described problem by providing a liquid crystal display whichexhibits a high contrast ratio while maintaining a wide viewing angleand high luminance.

In order to achieve that object, a first embodiment of the inventionincludes a liquid crystal display including a liquid crystal panel inwhich at least one of a pixel electrode and a common electrode formedwithin a pixel comprises repeating structures, and a light sourceilluminating said liquid crystal panel, wherein an angle range of lightincident from the light source on the liquid crystal panel along adirection of the repeating structures is narrower than that along anorthogonal direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing a liquid crystal display according to thefirst embodiment of the present invention.

FIG. 2 is a sectional view showing the liquid crystal display of FIG. 1.

FIG. 3 is a graph showing the light distribution characteristics in thevertical and horizontal directions of a backlight used in the firstembodiment.

FIG. 4 is a chart showing a difference in black luminance between theliquid crystal display of the present invention and a conventionalliquid crystal display.

FIG. 5 is a chart showing a difference in contrast ratio between theliquid crystal display of the present invention and the conventionalliquid crystal display.

FIG. 6 is a sectional view showing a liquid crystal display according toa second embodiment of the present invention.

FIG. 7 is a plan view showing the structure of a light-absorbinganisotropic member used in a liquid crystal display of the presentinvention.

FIG. 8 is a sectional view showing a liquid crystal display according toa third embodiment of the present invention.

FIG. 9 is a sectional view showing a liquid crystal display according toa fourth embodiment of the present invention.

FIG. 10 is a view showing a modified electrode structure used in theliquid crystal display of the present invention.

FIG. 11 is a view showing another modified electrode structure used inthe liquid crystal display of the present invention.

FIG. 12 is a perspective view showing terminal equipment to which thepresent invention is applied.

FIG. 13 is a sectional view showing the liquid crystal display accordingto a fifth embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

To widen the viewing angle, the present inventors have thoroughlyinvestigated the causes of low contrast ratio in liquid crystal displayswherein the pixel electrode or common electrode (or both) of a givenpixel has repeating structures arising from coupling pattern units.

Examples of a liquid crystal display with the above-described structureinclude an in-plane switching mode display, a fringe-field switchingmode display, and a patterned vertical alignment mode display.

The present inventors have discovered that in such a liquid crystaldisplay, the contrast ratio degrades because scattering occurs atintervals in the plane of a liquid crystal panel due to repeatingstructures of an electrode. In particular, it is believed that scatteredlight beams which occur at intervals are intensified by interference,and scattering from repeating portions within a pixel contributes mostsignificantly to degrading the contrast ratio.

Also, the present inventors have evaluated the contrast ratio using abacklight whose output angle range varies depending on the direction oflight incident on the liquid crystal panel and found from the resultthat the contrast ratio increases by limiting the incident light anglein a direction which coincides with the direction of the cycles of therepeating structures of an electrode within one pixel and that thecontrast ratio does not change by limiting the incident light angle in adirection orthogonal to that direction. Thus, it was found that theincident light angle need not be limited in a direction other than thedirection of the repeating structures of the electrode.

The present invention is therefore able to achieve a high contrast ratiowhile maintaining a wide viewing angle, by causing the incident anglerange along a direction of repeating structures of the electrode on theliquid crystal panel to be narrower than that along an orthogonaldirection.

Thus, in a first aspect of the present invention, a backlight whoseoutput angle range varies depending on the direction of light radiationis arranged behind a liquid crystal panel, and a direction in which theoutput angle range of light radiation from the backlight on the liquidcrystal panel is relatively narrow is made to coincide with thedirection of the repeating structures of an electrode formed within apixel.

Whereas conventional liquid crystal displays limit the incident lightangle in all directions around the normal axis, thereby impairing theviewing angle and luminance, with the arrangement of the presentinvention it becomes possible to minimize the sacrifice of the viewingangle and the luminance, and to increase the contrast ratio.

A second aspect of the present invention is that an output angle rangeratio between a direction in which the output angle range is wide and adirection in which the output angle range is narrow is 1:3 or more.

This ratio makes it possible to increase the contrast ratio to 1.7 timesor more than that of a conventional liquid crystal display whilemaintaining a wide viewing angle and to achieve a contrast ratio of1,000 or more.

A backlight (FIG. 3) whose half-luminance angle in the horizontaldirection is ±20° and whose half-luminance angle in the verticaldirection is ±60° was arranged behind the liquid crystal panel, and thecontrast ratio was evaluated as an example. The result showed that whenthe direction of the cycles of the repeating structures of an electrodewithin one pixel of the liquid crystal panel is made to coincide withthe incident direction whose half-luminance angle is ±20°, the blackluminance of the liquid crystal display is reduced to ⅔ or less thanthat of a conventional display, and the contrast ratio is increased by1.7 times or more. Since the contrast ratio of a conventional in-planeswitching mode liquid crystal display is approximately 600, the effectmakes it possible to achieve a contrast ratio of 1,000 or more.

Since the incident direction whose half-luminance angle is ±20° is madeto coincide with the direction of the cycles of the repeating structureof the electrode within one pixel, the viewing angle and the luminancein this direction are somewhat affected in this direction only. Theviewing angle and the luminance in all other directions can be kept aswide as that of a conventional liquid crystal display.

A third aspect of the present invention is a liquid crystal displayaccording to the first aspect of the present invention, furtherincluding a light-absorbing anisotropic member having repeatingstructures in which light-transmitting regions and light-shieldingregions are alternated in a plane, wherein the light-absorbinganisotropic member is arranged between the liquid crystal panel and thelight source, and a direction of repeating structures of the electrodecoincides with a direction of cycles of the repeating structures of thelight-absorbing anisotropic member.

In this aspect, only the incident light angle in a direction whichcoincides with the direction of the repeating cycles of thelight-transmitting regions and light-shielding regions can be limited bythe light-absorbing anisotropic member. Accordingly, this aspectincreases the contrast ratio while maintaining a wide viewing angle andhigh luminance, while permitting a conventional backlight to be usedwithout any modification.

A fourth aspect of the present invention is a liquid crystal displayaccording to the first aspect of the present invention, furtherincluding an anisotropic diffuser arranged between the liquid crystalpanel and the light source, wherein a direction of repeating structuresof the electrode coincides with a direction in which diffusivity of theanisotropic diffuser is small.

The anisotropic diffuser used in the fourth aspect of the presentinvention has a diffusing power for light radiation which variesdepending on the output angle. Accordingly, the range of an incidentangle on the liquid crystal panel can be controlled by an incidentdirection. As a result, there is produced the effect that a conventionalbacklight can be used without any modification, similarly to the thirdaspect of the present invention.

A fifth aspect of the present invention involves using a liquid crystaldisplay according to the first aspect of the present invention, andincluding an anisotropic lens sheet arranged between the liquid crystalpanel and the light source, wherein a direction in which an incidentangle range of light incident from the anisotropic lens sheet on theliquid crystal panel becomes relatively narrow, coincides with adirection of repeating structures of the electrode.

The anisotropic lens sheet used in the fifth aspect of the presentinvention can control the output angle range of light radiation from thebacklight in accordance with the incidence direction, similarly to thethird aspect of the present invention. Accordingly, in the fifth aspectof the present invention a conventional backlight can be used withoutany modification, similarly to the third aspect of the present inventionand fourth aspect of the present invention.

A sixth aspect of the present invention involves a liquid crystaldisplay wherein the vertical direction of display is the direction inwhich the angular range of light incident on the liquid crystal panel isrelatively narrow.

With this arrangement, even though the viewing angle and the luminancein the vertical direction are limited, the viewing angle and theluminance in the horizontal direction are normal. This allows thedisplay to be viewed with less discomfort than for a conventional liquidcrystal display and at the same time makes it possible to provide aliquid crystal display with a wide viewing angle and high luminancewhose contrast ratio has been increased as compared to a conventionalliquid crystal display.

A seventh aspect of the present invention is a liquid crystal displayaccording to the first aspect of the invention further comprising ananisotropic reflector plate arranged behind the light source, whereinthe anisotropic reflector plate has a reflection angle which variesdepending on a direction of light reflection, and a direction in whichthe reflection angle range is relatively narrow coincides with adirection of repeating structures of the electrode.

An eighth aspect of the present invention is terminal equipment havingthe above-described liquid crystal display. This invention makes itpossible to provide terminal equipment with a wider viewing angle andhigher contrast ratio than conventional terminal equipment.

As has been explained above, according to the present invention, aliquid crystal display which exhibits a high contrast ratio whilemaintaining a wide viewing angle and a high luminance can be provided bycausing the angular range of light incident from a light source on theliquid crystal panel to be relatively narrow in a direction coincidingwith the direction of the repeating structures of an electrode formedwithin a pixel.

A conventional backlight can be used by inserting a photoanisotropicmember between the liquid crystal panel and the backlight, forminganisotropy in the incident angle range of the incident direction fromthe backlight on the liquid crystal panel, and/or making the directionof the repeating cycles of the electrode structure coincide with adirection in which the incident angle range of incident light is narrow.

The present invention will be further explained in detail below on thebasis of preferred embodiments of the present invention and withreference to the drawings.

First Embodiment

FIG. 1 is a schematic plan view on an enlarged scale of a one-pixelregion of a liquid crystal display serving as a first embodiment of thepresent invention, and FIG. 2 shows a section taken along the line A-Bof the liquid crystal display shown in FIG. 1. The components in FIGS. 1and 2 are not drawn to scale, for ease of explanation.

As shown in FIG. 1, each of pixels of the liquid crystal displayaccording to this embodiment is located in a region delimited by signallines 11, and a scanning line 12 and common electrode line 13. The pixelcomprises a drain electrode line 14, pixel electrode line 15, commonelectrode 16, pixel electrode 17, and TFT transistor 18. Each of thepixel electrode 17 and common electrode 16 forms a comb-shaped electrodestructure and has repeating structures in the horizontal direction ofthe sheet surface shown in FIG. 1.

As for the TFT transistor 18 of each pixel, the source is connected tothe corresponding pixel electrode 17 through the corresponding pixelelectrode line 15 while the drain is connected to the correspondingsignal line 11 through the corresponding drain electrode line 14. TheTFT transistor 18 controls the signal input from the signal line 11 tothe pixel electrode line 15 on the basis of the presence/absence of avoltage applied to the scanning line 12. Although no storage capacitoris shown for the sake of clarity, in practice a storage capacity isformed at a predetermined position in accordance with the layout of theliquid crystal display.

In this embodiment, each of the common electrodes 16 and pixelelectrodes 17 is formed of a metal film. Each common electrode 16 isconnected to the corresponding common electrode line 13 of an underlyinglayer through a first contact hole 19. Each pixel electrode 17 isconnected to the corresponding pixel electrode line 15 of an underlyinglayer through a second contact hole 20.

As shown in FIG. 2, the liquid crystal display according to thisembodiment has a structure in which a backlight 34, TFT substrate 21,liquid crystal 23, and counter substrate 22 are stacked in order fromthe bottom layer. In the liquid crystal display, a portion formed bystacking the TFT substrate 21, liquid crystal 23, and counter substrate22 in this order constitutes a liquid crystal panel portion. Acold-cathode tube is used as the backlight 34.

The counter substrate 22 comprises a glass substrate 30, black matrix(BM) 33, protective film 31, and alignment layer 32. FIG. 2 envisions amonochrome liquid crystal panel to simplify the explanation of thepresent invention. The liquid crystal panel may instead be a colorliquid crystal panel in which an RGB color filter layer is formed on theglass substrate 30.

The TFT substrate 21 comprises at least a glass substrate 24, a firstinorganic insulating film (gate insulating film) 25, the signal lines11, the pixel electrodes 17, a second inorganic insulating film(protective film) 26, the common electrodes 16, and an alignment layer29, from the side of the backlight 34. Depending on the designguidelines for the liquid crystal display, an organic insulating filmmay be added on the second inorganic insulating film 26.

The first inorganic insulating film 25 is used to insulate the scanninglines 12 and common electrode lines 13 shown in FIG. 1 from upperlayers. The signal lines 11 and pixel electrodes 17 are formed on thefirst inorganic insulating film 25 and are insulated from upper layersby the second inorganic insulating film 26. The wiring width andthickness and the wiring material are selected for each of the signallines 11, scanning lines 12, and common electrode lines 13 such that thelines serve as desired wiring resistors. Each TFT transistor 18 isformed at a predetermined position of the upper portion of thecorresponding scanning line 12 using the first inorganic insulating film25 as a gate insulating film. The common electrodes 16 are arranged onthe second inorganic insulating film 26. The liquid crystal 23sandwiched between the TFT substrate 21 and the counter substrate 22 isdriven by a lateral electric field (the horizontal direction of thesheet surface shown in FIG. 2) formed between the common electrodes 16and the pixel electrodes 17.

The backlight 34 is arranged behind the TFT substrate 21. A surface ofthe glass substrate 24 which comes in contact with the backlight 34 hasa polarizer (not shown) to limit polarization of the backlight 34.

A polarizer (not shown) is positioned on the outer surface of the glasssubstrate 30. The polarization direction of the polarizer is orthogonalto that of the polarizer behind the glass substrate 24. For this reason,when no electric field is applied to the liquid crystal 23, light fromthe backlight 34 that has passed through the glass substrate 24 cannotpass through the glass substrate 30, and the liquid crystal displayshows black. The black mask (BM) 33, which blocks light, is disposed onthe inner surface of the glass substrate. The BM 33 shields the signallines 11, scanning lines 12, and common electrode lines 13 and virtuallydelimits the pixels.

FIG. 3 shows the light distribution characteristics in the vertical andhorizontal directions of the backlight 34 used in this embodiment. InFIG. 3, a solid line denoted by reference numeral 41 represents theluminance distribution in the vertical direction of the sheet surface ofFIG. 1 of the backlight used in this embodiment while a dotted linedenoted by reference numeral 42 represents the luminance distribution inthe horizontal direction of the sheet surface of FIG. 1 of the backlightused in this embodiment. According to FIG. 3, an angle at which aluminance is reduced to half of the front luminance (to be referred toas a half-luminance angle hereinafter) is ±60° in the vertical directionof the sheet surface of FIG. 1 of the backlight and is ±20 in thehorizontal direction of the sheet surface of FIG. 1 of the backlight.The ratio between the half-luminance angle in the vertical direction ofthe sheet surface of FIG. 1 of the backlight and that in the horizontaldirection of the sheet surface of FIG. 1 of the backlight is thus 3:1.

As described above, in this embodiment, the backlight 34 is arranged onthe back of the liquid crystal panel such that the direction of therepeating structures of the pixel electrode 17 and common electrode 16within one pixel coincides with a direction in which the half-luminanceangle of the backlight 34 is small. In other words, in the horizontaldirection of the sheet surface of FIG. 1, the direction of the repeatingstructures of the electrodes 16 and 17 coincides with a direction inwhich the incident angle range of light incident from the backlight 34on the liquid crystal panel is narrow.

A direction in which the backlight 34 has a narrow or widehalf-luminance angle has the same meaning as a direction in which theangular range of light incident from the backlight 34 on the liquidcrystal panel is narrow or wide, respectively.

FIGS. 4 and 5 show the black luminances and the contrast ratios,respectively, of the liquid crystal display of this embodiment and aconventional liquid crystal display. FIGS. 4 and 5 show that the blackluminance of the liquid crystal display according to this embodiment isreduced to ⅔ or less than that of the conventional display, and thecontrast ratio is increased by 1.7 times or more. Since the contrastratio of a conventional in-plane switching mode liquid crystal displayis approximately 600, the liquid crystal display of this embodiment canachieve a contrast ratio of 1,000 or more.

Since a direction in which the half-luminance angle of the backlight is±20° is made to coincide with the direction of the repeating structuresof the electrodes within one pixel, the viewing angle and the luminancein this direction is somewhat decreased. However, the half-luminanceangle is equivalent to that of a conventional liquid crystal display inany other direction, and thus a wide viewing angle and high luminancecan be maintained.

In this embodiment, each of the pixel electrodes 17 and commonelectrodes 16 has a linear comb-shaped electrode structure. However,even if each comb tooth portion of the comb-shaped electrode structuresis V-shaped (dogleg-shaped) or Z-shaped (zigzag-shaped), an increase inblack luminance can be suppressed by limiting the incident light anglein a direction which coincides with the direction of repetitions of thecomb tooth portions, such that the contrast ratio increases. Forexample, if each electrode structure is as shown in FIG. 10 or 11 inwhich Z-shaped comb teeth are formed repeatedly at regular intervals,the direction 55 in which the incident angle range of light incident onthe liquid crystal panel of the backlight is narrow may be chosen aseither the direction of an arrow shown in FIG. 10 or the direction ofthe arrow shown in FIG. 11.

In this embodiment, both the pixel electrodes and common electrodes areformed of a metal film. Even when they are formed of a transparentelectrode such as an ITO (indium tin oxide) film, the same effects canbe obtained.

Second Embodiment

FIG. 6 shows a sectional view of a liquid crystal display according to asecond embodiment of the present invention.

In this embodiment, as shown in FIG. 6, a light-absorbing anisotropicmember 35 is arranged between a backlight 34 and a TFT substrate 21, andthe direction of the repeating structures of electrodes within a pixelis made to coincide with the direction of the cycles of the repeatingstructures in the light-absorbing anisotropic member. Note that the sameliquid crystal display as in the first embodiment is used.

As shown in FIG. 7, the light-absorbing anisotropic member 35 hasrepeating structures of light-transmitting regions 51 andlight-shielding regions 52 (in the horizontal direction on the sheetsurface) and can limit the angle of incident light only in the directionof the repetitions. For example, Light Control Film (manufactured bySumitomo 3M Limited) commercially available as a viewing angle controlfilm can be used in this embodiment.

This embodiment increases the contrast ratio while maintaining a wideviewing angle and high luminance. Also, since the angle of lightincident from the backlight is limited by the light-absorbinganisotropic member, a conventional backlight can be used without anymodification.

Note that although this embodiment has explained in connection with alight-absorbing anisotropic member 35 whose light-transmitting regionsand light-shielding regions have a lattice structure corresponding tothe electrode structures within a pixel, the present invention is notlimited to this.

The photoanisotropic member may have any shape cooperating with theelectrode structures. For example, if the comb tooth portions of acomb-shaped electrode structure are dogleg-shaped, a light-absorbinganisotropic member with dogleg-shaped light-shielding regions can beused.

Third Embodiment

FIG. 8 shows a section of a liquid crystal display according to a thirdembodiment of the present invention.

The third embodiment is different from the second embodiment in that ananisotropic diffuser 36 is used instead of the light-absorbinganisotropic member, and a direction in which the diffusivity is small ismade to coincide with the direction of the repeating structures ofelectrodes. This increases the contrast ratio while maintaining a wideviewing angle and a high luminance. Since the directivity of a backlightis shaped by the anisotropic diffuser, a conventional backlight can beused without any modification. A holographic diffuser can be used as aspecific example of the anisotropic diffuser 36. A holographic diffuseris an aggregation of nonperiodic uneven patterns and can arbitrarily setthe diffusion angle of light. Accordingly, the holographic diffuser cancontrol the orthogonal diffusing power in accordance with the diffusionangle of a currently used backlight.

Fourth Embodiment

FIG. 9 is a sectional view showing a liquid crystal display according toa fourth embodiment of the present invention.

This embodiment is characterized in that an anisotropic lens sheet isarranged between a backlight and a liquid crystal panel, and thedirection of the repeating structures of electrodes is made tosubstantially coincide with a direction in which the angular range oflight incident on the liquid crystal panel is narrow.

More specifically, a prism sheet in which prisms are arranged in anarray or a lenticular lens in which plano-convex cylindrical lenses arearranged in an array can be used. The incident angles from such prismsor plano-convex cylindrical lenses on a liquid crystal panel aredifferent in respective directions orthogonal to the liquid crystalpanel. The arrangement of a prism sheet or a lenticular lens in the samemanner as in this embodiment permits a conventional backlight to be usedwithout any modification, similarly to the second embodiment and thirdembodiment.

As for the arrangement of the anisotropic lens sheet on the backlight,the incidence angles from the prisms (or cylindrical lenses) on theliquid crystal panel need to be respectively different only in twodirections orthogonal to each other and parallel to the liquid crystalpanel, regardless of whether the prisms (or lenses) are arranged suchthat their prism planes (or lens planes) face the liquid crystal panelside or backlight side.

Although this embodiment has been explained using a lattice-shapedanisotropic lens so as to fit the repeating structures of linearelectrodes, the present invention is not limited to this. Theanisotropic lens sheet may have any shape as far as it cooperates withthe electrode structures. For example, if the comb tooth portions of acomb-shaped electrode structure are dogleg-shaped, an anisotropic lenswith a dogleg shape can be used.

Fifth Embodiment

FIG. 13 is a sectional view showing a liquid crystal display accordingto a fifth embodiment of the present invention.

This embodiment is characterized in that an anisotropic reflector plate38 is arranged on a back of the backlight, and the direction of therepeating structures of electrodes is made to substantially coincidewith a direction in which the reflection angle range is narrow.

More specifically, a metal coating prism sheet in which prisms arearranged in an array can be used. The reflecting angles from such prismsare different in respective orthogonal directions. Light radiating fromthe backlight is reflected by the anisotropic reflector plate and passesthrough the backlight to the liquid crystal panel. Thus, the arrangementof a metal coating prism sheet in this embodiment permits a conventionalbacklight to be used without any modification, similarly to the secondembodiment and third embodiment.

Preferably, in the various forms of liquid crystal displays describedabove, the vertical direction of display is a direction in which theincident” angle range of light incident on a liquid crystal panel isnarrow. With this arrangement, even when the viewing angle in thevertical direction of display is limited, the viewing angle in thehorizontal direction of display exhibits characteristics as usual, thusallowing the display to be viewed with less discomfort than for aconventional liquid crystal module. In addition, since the direction ofthe repeating structures of electrodes within a pixel coincides with adirection in which the incident angle range of light incident on theliquid crystal panel is narrow, there can be provided a liquid crystalmodule with a wide viewing angle whose contrast ratio has been increasedas compared to a conventional liquid crystal module.

On the other hand, if it is desired to limit the viewing angle in thehorizontal direction, as might be desired for example in an automatedteller machine or a cell-phone, the horizontal direction may be chosenas the direction in which the angular range of light incident on theliquid crystal panel is narrow.

The present invention has been explained with reference to a number ofpreferred embodiments. However, liquid crystal displays according to thepresent invention are not limited to the various forms described above.A liquid crystal display obtained by changing or combining, asappropriate, the above-described various forms falls within the scope ofthe present invention.

For example, a light source may be a front light instead of a backlight.

Applications of the present invention include a liquid crystal displayused in terminal equipment (FIG. 12) such as a television, a monitor ofa personal computer, a medical monitor, a car navigation system, apachinko monitor or the like.

The previous description of embodiments is provided to enable a personskilled in the art to make and use the present invention. Moreover,various modifications to these embodiments will be readily apparent tothose skilled in the art, and the generic principles and specificexamples defined herein may be applied to other embodiments without theuse of inventive faculty. Therefore, the present invention is notintended to be limited to the embodiments described herein but is to beaccorded the widest scope as defined by the limitations of the claimsand equivalents.

1. A liquid crystal display comprising: a liquid crystal panel in whichat least one of a pixel electrode and a common electrode formed within apixel comprises repeating structures; a light source illuminating saidliquid crystal panel; and an anisotropic lens sheet arranged betweensaid liquid crystal panel and said light source, wherein an angularrange of light incident from said light source on said liquid crystalpanel is narrower along a direction of said repeating structures of saidelectrode than along an orthogonal direction; and wherein a direction inwhich an angular range of light incident from the anisotropic lens sheeton said liquid crystal panel is relatively narrow coincides with adirection of repeating structures of the electrode.